Ventricular and cerebral cysticercosis

The intracranial cysticercosis is mostly single or multiple, and can reside in different parts of the ventricular system, but the fourth intraventricular cysticercosis is the most common. Due to the difference in osmotic pressure, cerebrospinal fluid continuously infiltrates into the capsule of cysticercosis, and the volume of cysticercosis generally reaches 2 to 3 cm in diameter. The cysticercosis is attached to the ventricular wall or suspended in the ventricle, causing local ependymitis, subependymal gliosis, and deformation of a part of the ventricular system such as the third ventricle; cysticercosis floating in the ventricle can still make the chamber Interstitial, midbrain aqueduct, and fourth ventricle occlusion, obstructive hydrocephalus.

The clinical symptoms are mainly symptoms of increased intracranial pressure such as headache, vomiting, and papilledema. The diagnosis of cerebral cysticercosis mainly uses CT and MRI. CT ventriculography can delineate the location and contour of cysticercosis. Govindappa et al believe that MRI is superior to CT and is not radioactive. He used SE sequence and 3D-CISS (three-dimensional constructive interference in steady state) to compare 11 cases of cerebral cysticercosis. The results showed that the conventional sequences failed to show cysticercosis; SE-T1 weighted showed 9 cases of cystic wall The cystic cephalic section and cystic fluid were 4 and 2, respectively; SE-T2 weighted showed 3 and 4 cases of cyst wall and head section, respectively. In 3D-CISS, 11 cases of cerebral cysticercosis were visualized, and 7 cases showed the head section, cyst wall and cystic fluid. The 3D-CISS diagnosis is considered to be more sensitive.

The distribution of cysticercosis in the brain pool can also be in different parts, such as lateral fissure, basal pool and occipital pool. Can be single or grapem (racemose) with varying degrees of arachnoiditis. The diagnosis and operation of cysticercosis in the cerebral cistern is difficult. Sharma et al. successfully injected a case of grape-like cysticercosis with intrathecal gadodiamide. Zhang Jiadong and others believe that the cerebral cystic sinus is suspected, and the ventricular system is enlarged. However, CT ventriculography does not show cysticercosis in the ventricle. When the contrast agent does not flow into the occipital pool, it should be considered as a cerebral cysticercosis. It is recommended to do post-cranial fossa exploration. All 5 of them were confirmed by surgery.

Treating diseases: cerebral cysticercosis

Indication

1. Lateral ventricle, third ventricle, and fourth intraventricular cysticercosis, causing obstructive hydrocephalus.

2. Midbrain aqueduct occlusion and fourth ventricle mesopores adhesion.

3. Brain pool cerebral cysticercosis with arachnoiditis and traffic hydrocephalus.

Preoperative preparation

Patients often suffer from loss of water and electrolytes due to vomiting, or have a crisis of increased intracranial pressure, which is generally poor. The treatment should be supported first, and if necessary, the extraventricular drainage should be performed first to create conditions for the next operation.

Surgical procedure

Cerebral cysticercosis

Usually, the mid-frontal cortical incision is used. After entering the lateral ventricle, the patient's head is slightly tilted forward, so that the cysticercosis suspended in the ventricle moves to the frontal angle due to gravity. The cysticercosis capsule is thin and has a large tension. The cystic fluid can be aspirated first with a fine needle. After the reduction, the suction can be used to suck the capsule wall and gently remove it. The removal method of the third intraventricular cysticercosis may also take the mid-frontal cortical approach or the corpus callosum approach. The lateral ventricle interventricular space enters the third ventricle, and the lateral ventricle is obviously enlarged without difficulty.

2. Fourth intraventricular cysticercosis

Take the side, sitting or prone position. The midline of the posterior cranial fossa is incision, and the occipital bone is drilled and then expanded into a bone window with a diameter of 4 to 5 cm. The posterior arch of the atlas can not be bitten. The dura mater is cut in a "Y" shape, and the occipital sinus and the occipital sinus should be properly treated. The dura mater is directed to both sides, revealing the occipital pool, cerebellar tonsils, and cerebellar sac. The arachnoid membrane of the occipital pool is thickened and tarnished, and the tonsils can be squatted to varying degrees. Cut the arachnoid membrane of the occipital cistern and retract the tonsil to the sides. Sometimes the cystic worm is exposed by the hole in the fourth ventricle (Fig. 4.6.1.2-4). For example, in the fourth ventricle, the mesopores are not heavy, and the bipolar coagulation is adjacent to the mesopores, and the cerebellar amygdala is retracted, and the small cysticercosis can be removed from the fourth ventricle. If the mesopores are severely attached or the cysticercosis is large, it is necessary to separate the adhesion, enlarge the mesopores, or cut the chin to the top of the fourth ventricle, and then retract them with the brain plate to the sides, and the cysticercosis can be revealed. Because the cystic wall is thin and the tension is high, if the whole extraction is easy to break, it is better to use a fine needle to suction and decompress, and then remove it. In the seat surgery, the cysticercosis which is free in the fourth ventricle, due to its own gravity relationship, when the middle hole or the lower jaw is retracted, it is more likely to escape from the outside of the brain. For example, cysticercosis is located in the upper part of the fourth ventricle, or attached to the ventricular wall. Before the operation, there may be external drainage, and the physiological saline may be slowly injected into the cerebral ventricle to help the cysticercosis separate and escape from the ventricular wall.

In recent years, intraventricular cysticercosis has been advocated for neuroendoscopic removal. Bergsneider et al reported 10 cases of third and fourth intraventricular cysticercosis, 7 of which were accompanied by obstructive hydrocephalus. After removal of cysticercosis, 3 cases underwent a third ventricle ostomy at the same time, and 1 case underwent a transparent septum. Beijing Tiantan Hospital reported the use of neuroendoscopy in the treatment of 6 cases of cerebral cysticercosis, 2 cases in the lateral ventricle, 1 case in the fourth brain, 2 cases in the brain parenchyma, multiple cases (front of the aqueduct, interventricular space and occipital angle), considered After endoscopic surgery, the trauma is small, the operation is simple, and the head section and the cyst wall can be completely removed without complications.

3. Removal of cysticercosis in the cerebral cistern

The cysticercosis enucleation surgery is the same as the removal of the fourth ventricle cysticercosis. It is easy to remove cysticercosis by cutting open the arachnoid membrane of the pillow. Cerebral cysts often have lobes, located in the cerebellar lobes, cerebral cerebral horns or the ventral side of the brainstem. The cysticercosis resembles a bunch of grapes in the cerebral cistern, extending into the adjacent cerebral cistern, between the blood vessels and the nerves, and causing arachnoiditis and fibrosis in the brain, eventually causing traffic hydrocephalus. Surgical removal of the right incision in the midline of the posterior fossa, or a barbed incision behind the ear, careful separation of cysticercosis between the cystic worm and the blood vessels, nerves, and brain stem under the operating microscope. The cystic worm with large volume and high tension can puncture the liquid first. . Rinse with saline and gently pull outward with tweezers. Any adhesions must be cut after electrocoagulation under clear vision, and should not be pulled hard to avoid unnecessary damage. If the adhesion is too extensive, the separation will cause important structural damage and should be stopped.

4. Ventricular-peritoneal shunt

Both the intracranial cysticercosis and the cystic sinus in the cerebral cistern can be complicated by hydrocephalus. When the cerebrospinal fluid circulatory disorder cannot be removed after removing the intracranial or intracisternal cysticercosis, the ventriculo-peritoneal shunt is an important means of treating hydrocephalus. . The surgical injury is small and the shunting effect is good, but the shunt system still has the possibility of failure. According to Colli et al, 68% of patients need to be corrected for failure of the shunt system. In recent years, Wite reported that after shunt, patients were treated with hydrocortisone and/or antiparasitic drugs, and functional failure of the shunt system rarely occurred.